Level and Pressure Measurement

Malady of the 5 Monkeys

Malady of the 5 monkeys

The Malady of the 5 Monkeys is a modern day fable, inspired in part by the seperate experiments of G.R. Stephenson and Wolfgang Kohler studying certain behavioral in primates. In time, their results have become an apt parable.

Start with a cage containing five monkeys. Inside the cage, hang a banana on a string and place a set of stairs under it. Before long, a monkey will go to the stairs and start to climb toward the banana. As soon as he touches the stairs, spray all of the other monkeys with cold water. After a while, another monkey makes an attempt with the same result - all the others monkeys are sprayed with cold water. Pretty soon, when another monkey approaches the stairs, the remaining monkeys will try to prevent it.

Now, put away the cold water. Remove one monkey from the cage and replace it with a new one. The new monkey soon sees the banana and tries to climb the stairs, but to his horror, all the other monkeys attack him! After another attempt and resulting attack, he knows that if he tries to climb the stairs, he will be assaulted.

Next, remove another of the original five monkeys and replace it with a new one. The newcomer goes to the stairs and is attacked! The previous newcomer takes part in the punishment with great enthusiasm! Likewise, replace a third original monkey, then a fourth and finally the fifth.

Every time a new monkey approaches the stairs, he is attacked! The new monkeys have no idea why they are not permitted to climb the stairs nor why they are beating the newest monkey.

After replacing all of the original monkeys, none of the remaining monkeys have ever been sprayed with cold water. Yet, no monkey ever again approaches the stairs to try for the banana. Why? Because as far as they know, that's the way it has always been done.

At Keller America, we strive to make decisions based not solely on the past, but what will become the future.